The effects of viruses on bodily functions is the end result of changes occuring at the cellular and subcellular levels. The pathogenic changes at the cellular level are different for different combinations of viruses and host cells.
Important common viral infections are herpes dermatitis (including herpes labialis), herpes keratitis, herpes genitalis, herpes zoster, herpes encephalitis, infectious mononucleosis and cytomegalovirus infections all of which are caused by viruses belonging to the herpesvirus group. Other important viral diseases are influenza A and B which are caused by influenza A and B virus respectively. Another important common viral disease is viral hepatitis and especially hepatitis B virus infections are widely spread. Effective and selective antiviral agents are needed for the treatment of these diseases.
A most important common feature of the interaction between viruses and cells is the replication or transcription of the specific viral genetic information carried by viral nucleic acids. These viral nucleic acids are of two kinds, deoxyribonucleic acids (DNA) or ribonucleic acids (RNA). The primary genetic information of the cell is carried by cell DNA. DNA and RNA synthesis involves complex enzymes called DNA and RNA polymerases respectively. The genetic information is transferred to the new nucleic acid from a template nucleic acid. There are four general ways in which these nucleic acids can be replicated or transcribed. ##STR4## Processes 1 and 3 are used by cells. DNA viruses such as herpesviruses also use process 1 but the enzyme is different from that of the cell. RNA viruses such as influenza virus use process 2. There is a need for an effective antiviral agent preferably having a selective inhibiting effect on a specific viral function of the virus to be combated. It is, therefore, a general object of the present invention to provide a novel method for combating virus infections using an antiviral agent which exerts a selective inhibiting effect on viral functions but which exerts only a negligible inhibiting effect on functions of the host cells.